Deposition of smooth Cu(In, Ga)Se2 films from binary multilayers

Abstract Thin film photovoltaic devices based on CuInSe 2 (CIS) prepared by vacuum deposition have shown efficiencies greater than 17%. However, inexpensive large-area uniform-thickness photovoltaic devices are likely to require non-vacuum deposition techniques. We discuss in this paper electrodeposition of CIS films using multilayers of binary selenides and, post-deposition selenization and thermal annealing. A sequential electrodeposition of Cu/In 2 Se 3 /Cu 2− x Se on Mo-on-glass substrates was done potentiostatically at varying potentials, pH and deposition time. We have obtained crystalline chalcopyrite CuInSe 2 films with phase content greater than 95%. The surface of the films is specularly reflecting. We also present here a study of sputtered CIGS films using multilayers of binary selenides, and one-step electrodeposition of CIS films.